How to share blood pressure readings with your doctor

Bring a week of home readings taken the standard way: two readings one minute apart, every morning and every evening, for about seven days. Write down every number with the date and time, add the morning and evening averages, note anything unusual, and bring the cuff itself so it can be checked against the clinic's device.

From my side of the desk, a good log answers one question fast: what is this person's usual blood pressure at home?

The standard home protocol before a visit

The American Medical Association and Target:BP (a joint AHA and AMA program) describe the same routine for self-measured blood pressure, often shortened to SMBP:

The AMA calls seven days optimal. If your week gets cut short, a shorter run still helps, though the sources don't agree on the floor. Target:BP says two consecutive days is acceptable, while the National Association of Community Health Centers (NACHC) toolkit lists at least 3 days (12 readings) as the minimum. More days give a steadier average, so aim for seven and don't throw out a partial week.

The setup for each reading matters as much as the schedule. Sit quietly for a few minutes first, back supported, feet flat, arm resting at about heart level, and no talking. I've laid that out step by step in how to measure blood pressure at home.

What your doctor computes from the log

Mostly, the average. Target:BP's instructions are to average all the systolic and diastolic readings for the week into one systolic number and one diastolic number, and the NACHC toolkit describes that overall average as the figure used for diagnosis and treatment decisions. A single 162 on Thursday matters much less than where 28 readings land together.

What about day 1?

Some protocols drop it. A 2022 review of the "722" protocol (7 days, 2 sessions, 2 readings) in the Journal of Clinical Hypertension explains that European guidance discards the first day, because measurement bias is more likely at the start of a monitoring stretch. The same review describes the AHA/AMA version as 7 days, or 8 if the first day is discarded. Target:BP's own how-to page doesn't mention dropping it.

So whether day 1 counts depends on your doctor's protocol. Record it either way. Your doctor can leave out a day you wrote down, but they can't use one you skipped. If you want to know why first readings tend to run high, see why your first blood pressure reading is often higher.

Why morning and evening get split

Doctors often look at the morning and evening averages separately, because the two can differ and medication timing can affect either one. That's why the time of each reading belongs in the log. There's more on this in morning vs evening blood pressure.

What makes a log useful

Here's what I'd want to see on every line:

At the bottom, add three averages: morning, evening, and overall. If your doctor follows a drop-day-1 protocol, it's easy for them to recompute, but having your numbers there saves time in a short visit.

Target:BP also suggests keeping a written log in addition to the monitor's memory, as a backup. Monitor memory has no notes, and if two people share the cuff, it has both of you in it.

A printable blood pressure log works fine. So does a blood pressure app, as long as it keeps the time stamp and lets you add notes.

What makes a log hard to use

These are all common, and each one makes the average harder to trust.

• Random times. Three readings Tuesday at lunch, nothing Wednesday, one at 11 p.m. Friday. There's no morning or evening pattern to compare.
• Single readings. One reading per session means no average for that session and twice the noise.
• Rounded numbers. A column of 140s and 130s usually means someone was rounding. Write what the screen says.
• Only the worrying ones. Measuring only when you feel off, or only writing down the scary numbers, pulls the average up.
• Retaking until it looks nice. Same problem in the other direction.
• Missing context. A 171/98 with no note leaves your doctor guessing. A 171/98 with "forgot morning pill, argued with the printer" tells a story.
• Mixed devices. Two different cuffs in one week can mean two different baselines.

Bring your cuff

Bring the monitor along with the log. Harvard Health suggests asking a nurse to take one reading with your monitor and one with the office device. The AMA's guidance is that home readings should come from a validated upper-arm device with a cuff sized to your arm, and the NACHC toolkit lists checking a home monitor against a more accurate machine as a routine care-team task.

That check answers two practical questions. Is your device reading in the right neighborhood, and is the cuff the right size for your arm? Expect the two devices to differ a little. Your doctor or nurse can tell you whether the gap is big enough to matter.

When not to wait for the appointment

Some readings shouldn't sit in a log until your next visit. Cleveland Clinic's guidance:

• 180/120 or higher with any symptoms (chest pain, severe headache, vision changes, slurred speech, weakness, confusion): call 911 or your local emergency number.
• 180/120 or higher with no symptoms: rest for several minutes and measure again. If it's still that high, seek medical care. If it comes down, call your usual doctor's office and tell them what happened.

If your averages are running well above the target your doctor gave you, call the office rather than waiting weeks for a scheduled visit.

The checklist

Before the week starts

• Validated upper-arm monitor, with a cuff that fits your arm
• Ask your doctor which protocol they want (7 days? drop day 1?) and whether to measure before or after morning medication
• Pick two times you can stick to, one morning and one evening

During the week

• Two readings, one minute apart, each session
• Same arm, same position, same chair
• Write the exact numbers, the date, and the time
• Add a note for anything unusual: missed or late dose, symptoms, caffeine, exercise, pain, poor sleep

Before the visit

• Morning, evening, and overall averages at the bottom
• The full list of readings, including the ones you didn't like
• Your monitor and cuff
• Your current medication list, with doses and the times you take them

Common questions

Can I just bring the monitor and let the doctor read the memory?

Bring it, but don't rely on it alone. Target:BP recommends a written log with device memory as the backup. The memory won't tell anyone about the missed pill or the 3 a.m. phone call.

Should I leave out readings I think were wrong?

Keep them in and add a note, such as "cuff slipped" or "talking on the phone." Deleting readings by hand is how a log ends up looking better than the person's blood pressure.

When should I start before my appointment?

Ideally, finish the seven days in the week or two right before the visit, so the numbers reflect your current medications and routine.

Is an app as good as a paper log?

It can be better, if it records the time of every reading, keeps both readings from each session, and lets you add notes. The format matters less than following the protocol consistently.

How BP Log helps

BP Log's guided flow times two readings a minute apart and averages them automatically, and you can tag a reading with things like a missed medication or caffeine. The free doctor visit report PDF puts your averages and an AM vs PM chart on page 1, then lists every reading, split AM and PM with averages, from page 2. You can also export everything as a CSV file.